package demo04;

import java.util.Random;

public class Test01 {
    public static void main(String[] args) {
        Random rd=new Random();
        int a = rd.nextInt(9999)+1;
        String s=a+"";
        while (true){
            if (s.length()==4){
                break;
            }else{
                s="0"+s;
            }

        }System.out.println(s);
    }
}
